This invention relates to logging plugs for use in oil, gas and other wells.
To ascertain parameters of well operations such as pressure, temperature and flow rate one or more logging tools are run down the well on a logging or slick line cable, which will subsequently be referred to by the further alternative term wireline. As many of these parameters must be measured while the pressure in the perforation zone is different from that obtaining in the upper part of the well down which the logging tool is run, it is necessary for the wireline to be passed through a logging plug which maintains a good, but not perfect seal, with the wire, and which is itself sealable within a nipple incorporated in production tubing, by-pass tubing or the well casing.
Considerations arising from a typical employment of a conventional logging plug will now be discussed with reference to the accompanying diagrammatic drawings in which: